feat: Passwordless cross-device authentication

- Arkitektur: docs/auth/passwordless-architecture.md
- Backend: iom/quixzoom-auth-service/ (FastAPI + Redis)
- Webb: quixzoom-market-pages/se/login/ (QR-kod + polling)
- App: iom/quixzoom-app/src/features/auth/ (push + deep links)

Flöde: QR-kod → app-godkännande → webb-inloggad

landvex/node_modules/one-time/async.js

@@ -0,0 +1,43 @@
+'use strict';
+
+var name = require('fn.name');
+
+/**
+ * Wrap callbacks to prevent double execution.
+ *
+ * @param {Function} fn Function that should only be called once.
+ * @returns {Function} A async wrapped callback which prevents multiple executions.
+ * @public
+ */
+module.exports = function one(fn) {
+  var called = 0
+    , value;
+
+  /**
+   * The function that prevents double execution.
+   *
+   * @async
+   * @public
+   */
+  async function onetime() {
+    if (called) return value;
+
+    called = 1;
+    value = await fn.apply(this, arguments);
+    fn = null;
+
+    return value;
+  }
+
+  //
+  // To make debugging more easy we want to use the name of the supplied
+  // function. So when you look at the functions that are assigned to event
+  // listeners you don't see a load of `onetime` functions but actually the
+  // names of the functions that this module will call.
+  //
+  // NOTE: We cannot override the `name` property, as that is `readOnly`
+  // property, so displayName will have to do.
+  //
+  onetime.displayName = name(fn);
+  return onetime;
+};